Evaluation of the benefits, harms and cost‐effectiveness of potential alternatives to iFOBT testing for colorectal cancer screening in Australia

The Australian National Bowel Cancer Screening Program (NBCSP) will fully roll‐out 2‐yearly screening using the immunochemical Faecal Occult Blood Testing (iFOBT) in people aged 50 to 74 years by 2020. In this study, we aimed to estimate the comparative health benefits, harms, and cost‐effectiveness of screening with iFOBT, versus other potential alternative or adjunctive technologies. A comprehensive validated microsimulation model, Policy1‐Bowel, was used to simulate a total of 13 screening approaches involving use of iFOBT, colonoscopy, sigmoidoscopy, computed tomographic colonography (CTC), faecal DNA (fDNA) and plasma DNA (pDNA), in people aged 50 to 74 years. All strategies were evaluated in three scenarios: (i) perfect adherence, (ii) high (but imperfect) adherence, and (iii) low adherence. When assuming perfect adherence, the most effective strategies involved using iFOBT (annually, or biennially with/without adjunct sigmoidoscopy either at 50, or at 54, 64 and 74 years for individuals with negative iFOBT), or colonoscopy (10‐yearly, or once‐off at 50 years combined with biennial iFOBT). Colorectal cancer incidence (mortality) reductions for these strategies were 51–67(74–80)% in comparison with no screening; 2‐yearly iFOBT screening (i.e. the NBCSP) would be associated with reductions of 51(74)%. Only 2‐yearly iFOBT screening was found to be cost‐effective in all scenarios in context of an indicative willingness‐to‐pay threshold of A$50,000/life‐year saved (LYS); this strategy was associated with an incremental cost‐effectiveness ratio of A$2,984/LYS–A$5,981/LYS (depending on adherence). The fully rolled‐out NBCSP is highly cost‐effective, and is also one of the most effective approaches for bowel cancer screening in Australia

Power to identify a genetic predictor of antihypertensive drug response using different methods to measure blood pressure response

<p>Abstract</p> <p>Background</p> <p>To determine whether office, home, ambulatory daytime and nighttime blood pressure (BP) responses to antihypertensive drug therapy measure the same signal and which method provides greatest power to identify genetic predictors of BP response.</p> <p>Methods</p> <p>We analyzed office, home, ambulatory daytime and nighttime BP responses in hypertensive adults randomized to atenolol (N = 242) or hydrochlorothiazide (N = 257) in the Pharmacogenomic Evaluation of Antihypertensive Responses Study. Since different measured BP responses may have different predictors, we tested the "same signal" model by using linear regression methods to determine whether known predictors of BP response depend on the method of BP measurement. We estimated signal-to-noise ratios and compared power to identify a genetic polymorphism predicting BP response measured by each method separately and by weighted averages of multiple methods.</p> <p>Results</p> <p>After adjustment for pretreatment BP level, known predictors of BP response including plasma renin activity, race, and sex were independent of the method of BP measurement. Signal-to-noise ratios were more than 2-fold greater for home and ambulatory daytime BP responses than for office and ambulatory nighttime BP responses and up to 11-fold greater for weighted averages of all four methods. Power to identify a genetic polymorphism predicting BP response was directly related to the signal-to-noise ratio and, therefore, greatest with the weighted averages.</p> <p>Conclusion</p> <p>Since different methods of measuring BP response to antihypertensive drug therapy measure the same signal, weighted averages of the BP responses measured by multiple methods minimize measurement error and optimize power to identify genetic predictors of BP response.</p

Preparation and Characterization of the Extracellular Domain of Human Sid-1

In C. elegans, the cell surface protein Sid-1 imports extracellular dsRNA into the cytosol of most non-neuronal cells, enabling systemic spread of RNA interference (RNAi) throughout the worm. Sid-1 homologs are found in many other animals, although for most a function for the protein has not yet been established. Sid-1 proteins are composed of an N-terminal extracellular domain (ECD) followed by 9–12 predicted transmembrane regions. We developed a baculovirus system to express and purify the ECD of the human Sid-1 protein SidT1. Recombinant SidT1 ECD is glycosylated and spontaneously assembles into a stable and discrete tetrameric structure. Electron microscopy (EM) and small angle x-ray scattering (SAXS) studies reveal that the SidT1 ECD tetramer is a compact, puck-shaped globular particle, which we hypothesize may control access of dsRNA to the transmembrane pore. These characterizations provide inroads towards understanding the mechanism of this unique RNA transport system from structural prospective

Aging syndrome genes and premature coronary artery disease

BACKGROUND: Vascular disease is a feature of aging, and coronary vascular events are a major source of morbidity and mortality in rare premature aging syndromes. One such syndrome is caused by mutations in the lamin A/C (LMNA) gene, which also has been implicated in familial insulin resistance. A second gene related to premature aging in man and in murine models is the KLOTHO gene, a hypomorphic variant of which (KL-VS) is significantly more common in the first-degree relatives of patients with premature coronary artery disease (CAD). We evaluated whether common variants at the LMNA or KLOTHO genes are associated with rigorously defined premature CAD. METHODS: We identified 295 patients presenting with premature acute coronary syndromes confirmed by angiography. A control group of 145 patients with no evidence of CAD was recruited from outpatient referral clinics. Comprehensive haplotyping of the entire LMNA gene, including the promoter and untranslated regions, was performed using a combination of TaqMan(® )probes and direct sequencing of 14 haplotype-tagging single nucleotide polymorphisms (SNPs). The KL-VS variant of the KLOTHO gene was typed using restriction digest of a PCR amplicon. RESULTS: Two SNPs that were not in Hardy Weinberg equilibrium were excluded from analysis. We observed no significant differences in allele, genotype or haplotype frequencies at the LMNA or KLOTHO loci between the two groups. In addition, there was no evidence of excess homozygosity at the LMNA locus. CONCLUSION: Our data do not support the hypothesis that premature CAD is associated with common variants in the progeroid syndrome genes LMNA and KLOTHO

Tracing amino acid exchange during host-pathogen interaction by combined stable-isotope time-resolved Raman spectral imaging

This study investigates the temporal and spatial interchange of the aromatic amino acid phenylalanine (Phe) between human retinal pigment epithelial cell line (ARPE-19) and tachyzoites of the apicomplexan protozoan parasite Toxoplasma gondii (T. gondii). Stable isotope labelling by amino acids in cell culture (SILAC) is combined with Raman micro-spectroscopy to selectively monitor the incorporation of deuterium-labelled Phe into proteins in individual live tachyzoites. Our results show a very rapid uptake of L-Phe(D8) by the intracellular growing parasite. T. gondii tachyzoites are capable of extracting L-Phe(D8) from host cells as soon as it invades the cell. L-Phe(D8) from the host cell completely replaces the L-Phe within T. gondii tachyzoites 7–9 hours after infection. A quantitative model based on Raman spectra allowed an estimation of the exchange rate of Phe as 0.5–1.6 × 104 molecules/s. On the other hand, extracellular tachyzoites were not able to consume L-Phe(D8) after 24 hours of infection. These findings further our understanding of the amino acid trafficking between host cells and this strictly intracellular parasite. In particular, this study highlights new aspects of the metabolism of amino acid Phe operative during the interaction between T. gondii and its host cell

Endothelin-1 as a neuropeptide: neurotransmitter or neurovascular effects?

Endothelin-1 (ET-1) is an endothelium-derived peptide that also possesses potent mitogenic activity. There is also a suggestion the ET-1 is a neuropeptide, based mainly on its histological identification in both the central and peripheral nervous system in a number of species, including man. A neuropeptide role for ET-1 is supported by studies showing a variety of effects caused following its administration into different regions of the brain and by application to peripheral nerves. In addition there are studies proposing that ET-1 is implicated in a number of neural circuits where its transmitter affects range from a role in pain and temperature control to its action on the hypothalamo-neurosecretory system. While the effect of ET-1 on nerve tissue is beyond doubt, its action on nerve blood flow is often ignored. Here, we review data generated in a number of species and using a variety of experimental models. Studies range from those showing the distribution of ET-1 and its receptors in nerve tissue to those describing numerous neurally-mediated effects of ET-1

Transcriptional Profiling of Non-Small Cell Lung Cancer Cells with Activating EGFR Somatic Mutations

Activating somatic mutations in epidermal growth factor receptor (EGFR) confer unique biologic features to non-small cell lung cancer (NSCLC) cells, but the transcriptional mediators of EGFR in this subgroup of NSCLC have not been fully elucidated.Here we used genetic and pharmacologic approaches to elucidate the transcriptomes of NSCLC cell lines. We transcriptionally profiled a panel of EGFR-mutant and -wild-type NSCLC cell lines cultured in the presence or absence of an EGFR tyrosine kinase inhibitor. Hierarchical analysis revealed that the cell lines segregated on the basis of EGFR mutational status (mutant versus wild-type), and expression signatures were identified by supervised analysis that distinguished the cell lines based on mutational status (wild-type versus mutant) and type of mutation (L858R versus Delta746-750). Using an EGFR mutation-specific expression signature as a probe, we mined the gene expression profiles of two independent cohorts of NSCLC patients and found the signature in a subset. EGFR tyrosine kinase inhibitor treatment regulated the expression of multiple genes, and pharmacologic inhibition of the protein products of two of them (PTGS2 and EphA2) inhibited anchorage-independent growth in EGFR-mutant NSCLC cells.We have elucidated genes not previously associated with EGFR-mutant NSCLC, two of which enhanced the clonogenicity of these cells, distinguishing these mediators from others previously shown to maintain cell survival. These findings have potential clinical relevance given the availability of pharmacologic tools to inhibit the protein products of these genes

Ocular medicines in children: the regulatory situation related to clinical research

<p>Abstract</p> <p>Background</p> <p>Many ocular medications are prescribed for paediatric patients, but the evidence for their rational use is very scant. This study was planned to compare the availability and the licensing status of ocular medications marketed in Italy, the United Kingdom (UK), and the United States of America (USA) related to the amount of published and un-published RCTs testing these drugs in the paediatric population.</p> <p>Methods</p> <p>A quantitative analysis was performed to evaluate the number of ocular medications with a paediatric license in Italy, the UK, and the USA. A literature search was also performed in MEDLINE, EMBASE, and The Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) on ophthalmic pharmacological therapy in children aged < 18 years, published up to December 2010. A search in the international clinical trial registries, the list of paediatric investigation plans (PIPs) approved by European Medicines Agency (EMA), and the table of medicines with new paediatric information approved by Food and Drug Administration (FDA) was also performed.</p> <p>Results</p> <p>In all, of 197 drugs identified, 68 (35%) single drugs are licensed for paediatric use at least in one considered country, while 23 (12%) were marketed in all three countries. More specifically, in Italy 43 single drugs (48% of those marketed) had a paediatric license, while 39 (64%) did in the UK and 22 (54%) did in the USA. Only 13 drugs were marketed with a paediatric license in all countries.</p> <p>The percentage of drugs licensed for paediatric use and for which at least one RCT had been performed ranged between 51% in Italy and 55% in the USA. No published RCTs were found for 11 (48%) drugs licensed for paediatric use in all three countries. In all, 74 (35%) of the retrieved RCTs involved mydriatic/cycloplegic medications.</p> <p>A total of 62 RCTs (56% completed) on 46 drugs were found in the international clinical trial registries. Cyclosporin and bevacizumab were being studied in many ongoing trials. Twenty-six drugs had new paediatric information approved by FDA based on new paediatric clinical trials, while only 4 PIPs were approved by EMA.</p> <p>Conclusions</p> <p>There is a pressing need for further research and clinical development in the pediatric ophthalmic area, where effective up-to-date treatments, and additional research and education on use in children, remain priorities.</p

Do community medicine residency trainees learn through journal club? An experience from a developing country

BACKGROUND: Journal clubs are an internationally recognized teaching tool in many postgraduate medical education fields. In developing countries lack of funds for current print materials may have limited journal club use. But with advancing information technology trainees in developing countries increasingly have more access to high quality journals online. However, we are aware of no studies describing journal club existence and effectiveness in postgraduate medical training in Pakistan. Also we have found no published effectiveness studies of this teaching modality in Community Medicine (Public Health) in any country. This study evaluated the effectiveness of Community Medicine (Public Health) Resident Journal Club (CMR-JC) in Aga Khan University, Pakistan using international criteria for successful journal clubs (2 years continuous existence and more than 50% attendance) and examining resident and alumni satisfaction. METHODS: Journal club effectiveness criteria were searched using electronic search databases. Departmental records were reviewed from September1999–September 2005. Ninety percent of residents and alumni of Community Medicine Residency Programme participated voluntarily in a confidential survey. RESULTS: The CMR-JC was regularly conducted. More than 95% of residents attended. (Total residents in the CMR-Programme: 32). Twenty-seven out of 29 current residents/alumni responded to the anonymous questionnaire. Acquisition of critical appraisal skills (23 respondents) and keeping up with current literature (18 respondents) were the two most important objectives achieved. Respondents recommended improved faculty participation and incorporating a structured checklist for article review. CONCLUSION: CMR-JC fulfils criteria for effective journal clubs. Residents and alumni agree CMR-JC meets its objectives. Incorporating suggested recommendations will further improve standards. The journal club learning modality should be included in residency training programs in developing countries. Effective use of online resources to support journal clubs is demonstrated as a successful alternative to excessive expenditure for obtaining print journals. Those trying to start or improve journal clubs can benefit from our experience

Mind-wandering and alterations to default mode network connectivity when listening to naturalistic versus artificial sounds

Naturalistic environments have been demonstrated to promote relaxation and wellbeing. We assess opposing theoretical accounts for these effects through investigation of autonomic arousal and alterations of activation and functional connectivity within the default mode network (DMN) of the brain while participants listened to sounds from artificial and natural environments. We found no evidence for increased DMN activity in the naturalistic compared to artificial or control condition, however, seed based functional connectivity showed a shift from anterior to posterior midline functional coupling in the naturalistic condition. These changes were accompanied by an increase in peak high frequency heart rate variability, indicating an increase in parasympathetic activity in the naturalistic condition in line with the Stress Recovery Theory of nature exposure. Changes in heart rate and the peak high frequency were correlated with baseline functional connectivity within the DMN and baseline parasympathetic tone respectively, highlighting the importance of individual neural and autonomic differences in the response to nature exposure. Our findings may help explain reported health benefits of exposure to natural environments, through identification of alterations to autonomic activity and functional coupling within the DMN when listening to naturalistic sounds